diff --git a/gfan-shared.patch b/gfan-shared.patch
new file mode 100644
index 0000000..e5ff486
--- /dev/null
+++ b/gfan-shared.patch
@@ -0,0 +1,114 @@
+--- Makefile.orig	2017-09-28 07:44:12.000000000 -0600
++++ Makefile	2018-04-12 21:33:16.347207853 -0600
+@@ -125,7 +125,7 @@ OPTFLAGS    =  -DGMPRATIONAL -Wuninitial
+ #OPTFLAGS    =  -DGMPRATIONAL -Wuninitialized -fno-omit-frame-pointer -O3 -msse2 -ftree-vectorizer-verbose=2 -ffast-math #-DNDEBUG
+ #OPTFLAGS    =  -DGMPRATIONAL -Wuninitialized -fno-omit-frame-pointer -O3 -mavx -msse2 -ftree-vectorizer-verbose=2 -ffast-math #-DNDEBUG
+ 
+-CFLAGS	  = $(OPTFLAGS) $(GPROFFLAG) $(STACTDUMP_OPTIONS) $(ADDITIONALINCLUDEOPTIONS) -std=c++0x -g $(CDDDEFINE_PREFIX) #-pedantic
++CFLAGS	  = $(OPTFLAGS) $(GPROFFLAG) $(STACTDUMP_OPTIONS) $(ADDITIONALINCLUDEOPTIONS) -std=c++11 -g $(CDDDEFINE_PREFIX) #-pedantic
+ #CFLAGS	  = $(OPTFLAGS) $(GPROFFLAG) $(STACTDUMP_OPTIONS) $(ADDITIONALINCLUDEOPTIONS) -D_GLIBCXX_DEBUG -std=c++0x -g $(CDDDEFINE_PREFIX) #-pedantic
+ CCFLAGS	  = $(CFLAGS)
+ FFLAGS	  = $(OPTFLAGS)
+@@ -211,15 +211,6 @@ CATSOBJECTS =	lp_cdd.o \
+ 	tropicaldeterminant.o \
+ 	determinantpoly.o \
+ 	traverser_sphere.o \
+-	gfanlib_zcone.o \
+-	gfanlib_symmetry.o \
+-	gfanlib_symmetriccomplex.o \
+-	gfanlib_polyhedralfan.o \
+-	gfanlib_zfan.o \
+-	gfanlib_polymakefile.o \
+-	gfanlib_mixedvolume.o \
+-	gfanlib_circuittableint.o \
+-	gfanlib_paralleltraverser.o \
+ 	padic.o \
+ 	integergb.o \
+ 	traverser_resultantfan.o \
+@@ -227,7 +218,6 @@ CATSOBJECTS =	lp_cdd.o \
+ 	traverser_resultantfanspecialization.o \
+ 	myassert.o \
+ 	traverser_bsptree.o \
+-	gfanlib_traversal.o \
+ 	tropicalcurve.o \
+ 	packedmonomial.o \
+ 	gmpallocator.o \
+@@ -387,14 +377,24 @@ GFANLIBFILES= 	gfanlib.h \
+ 				gfanlib_tropicalhomotopy.h \
+ 	#			gfanlib_tableau.h \   we do not yet support this one
+ 
++GFANLIBOBJECTS =		gfanlib_polyhedralfan.o \
++				gfanlib_zcone.o \
++				gfanlib_symmetriccomplex.o \
++				gfanlib_polymakefile.o \
++				gfanlib_zfan.o \
++				gfanlib_symmetry.o \
++				gfanlib_circuittableint.o \
++				gfanlib_mixedvolume.o \
++				gfanlib_paralleltraverser.o \
++				gfanlib_traversal.o
+ 
+ EXECS	  = $(MAIN)
+ 
+ # When compiling symmetrictraversal.cpp as any other file, it causes the program to crash in certain situations.
+ # (compiling with gcc version 4.7.2 and running gfan _tropicaltraverse on a starting cone for Grassmann3_7)
+ # Either this is a bug in the code or in the compiler. The bug disappears by compiling with -fno-guess-branch-probability
+-src/symmetrictraversal.o: src/symmetrictraversal.cpp
+-	$(CXX) $(CFLAGS) -fno-guess-branch-probability  -c src/symmetrictraversal.cpp -o src/symmetrictraversal.o
++#src/symmetrictraversal.o: src/symmetrictraversal.cpp
++#	$(CXX) $(CFLAGS) -fno-guess-branch-probability  -c src/symmetrictraversal.cpp -o src/symmetrictraversal.o
+ # If compiling with clang, use the line below instead:
+ #	$(CXX) $(CFLAGS) -c src/symmetrictraversal.cpp -o src/symmetrictraversal.o
+ 
+@@ -406,6 +406,7 @@ OBJECTS = 	$(addprefix src/,$(SOPLEX_OBJ
+ 		$(SAGE_OBJECTS) \
+ 		$(addprefix src/,$(CATSOBJECTS)) \
+ 		$(addprefix src/,$(APPOBJECTS)) \
++		src/libgfan.so \
+ 		src/symmetrictraversal.o
+ 
+ all: $(MAIN)
+@@ -420,7 +421,42 @@ default: $(OBJECTS) $(ADDITIONALOBJECTS)
+ 
+ $(MAIN): $(OBJECTS)
+ #	$(CCLINKER) $(OBJECTS) $(ADDITIONALLINKOPTIONS) $(GPROFFLAG) -lpthread  -o $(MAIN)
+-	$(CCLINKER) $(OBJECTS) $(ADDITIONALLINKOPTIONS) $(GPROFFLAG) -lpthread -rdynamic -o $(MAIN)
++	$(CCLINKER) $(OBJECTS) $(ADDITIONALLINKOPTIONS) $(GPROFFLAG) -L src -lgfan -lpthread -o $(MAIN)
++
++src/libgfan.so: $(addprefix src/,$(GFANLIBOBJECTS))
++	$(CCLINKER) $(CCFLAGS) $(ADDITIONALLINKOPTIONS) -shared -Wl,-h,libgfan.so.0 -o src/libgfan.so.0.0.0 $^ -lgmp -lpthread
++	ln -s libgfan.so.0.0.0 src/libgfan.so.0
++	ln -s libgfan.so.0 src/libgfan.so
++
++src/gfanlib_polyhedralfan.o: src/gfanlib_polyhedralfan.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_zcone.o: src/gfanlib_zcone.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_symmetriccomplex.o: src/gfanlib_symmetriccomplex.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_polymakefile.o: src/gfanlib_polymakefile.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_zfan.o: src/gfanlib_zfan.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_symmetry.o: src/gfanlib_symmetry.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_circuittableint.o: src/gfanlib_circuittableint.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_mixedvolume.o: src/gfanlib_mixedvolume.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_paralleltraverser.o: src/gfanlib_paralleltraverser.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
++
++src/gfanlib_traversal.o: src/gfanlib_traversal.cpp
++	$(CXX) $(CCFLAGS) -fPIC -c $< -o $@
+ 
+ release:
+ 	rm -f -r $(RELEASEDIR)/*
diff --git a/gfan-warning.patch b/gfan-warning.patch
index 00230da..406a1e8 100644
--- a/gfan-warning.patch
+++ b/gfan-warning.patch
@@ -176,16 +176,26 @@
  
  
 --- src/gfanlib_tropicalhomotopy.h.orig	2017-06-20 08:47:37.000000000 -0600
-+++ src/gfanlib_tropicalhomotopy.h	2017-08-19 20:27:59.920417245 -0600
-@@ -454,7 +454,7 @@ template<class mvtyp, class mvtypDouble,
++++ src/gfanlib_tropicalhomotopy.h	2018-04-10 20:44:53.417106582 -0600
+@@ -454,10 +454,14 @@ template<class mvtyp, class mvtypDouble,
  			//chioices are "relative" so no update is needed.
  
  			choices=parent.choices;
 -			int numberToDrop=(subconfigurationIndex!=0) ? numberToDrop=k+1 : 0;
-+			int numberToDrop=(subconfigurationIndex!=0) ? k+1 : 0;
+-
+-			choices[subconfigurationIndex-1].first-=numberToDrop;
+-			choices[subconfigurationIndex-1].second-=numberToDrop;
++			int numberToDrop;
++			if (subconfigurationIndex!=0) {
++				numberToDrop = k+1;
++				choices[subconfigurationIndex-1].first-=numberToDrop;
++				choices[subconfigurationIndex-1].second-=numberToDrop;
++			} else {
++				numberToDrop = 0;
++			}
  
- 			choices[subconfigurationIndex-1].first-=numberToDrop;
- 			choices[subconfigurationIndex-1].second-=numberToDrop;
+ 			denominator=parent.denominator;
+ 			int offsetOld=0;
 --- src/gfanlib_zcone.cpp.orig	2017-06-20 08:47:37.000000000 -0600
 +++ src/gfanlib_zcone.cpp	2017-08-19 19:35:36.550662558 -0600
 @@ -16,8 +16,8 @@
diff --git a/gfan.spec b/gfan.spec
index cddfa9e..4ca078d 100644
--- a/gfan.spec
+++ b/gfan.spec
@@ -1,6 +1,6 @@
 Name:           gfan
 Version:        0.6.2
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        Software for Computing Gröbner Fans and Tropical Varieties
 License:        GPLv2+
 URL:            http://home.math.au.dk/jensen/software/gfan/gfan.html
@@ -11,6 +11,8 @@ Patch0:         %{name}-warning.patch
 # Treat plain "gfan" call as "gfan_bases" call (as done in previous versions)
 # instead of warning that "gfan_bases" should be called and exiting
 Patch1:         %{name}-permissive.patch
+# Build a shared library
+Patch2:         %{name}-shared.patch
 
 BuildRequires:  cddlib-devel
 BuildRequires:  gcc-c++
@@ -20,6 +22,8 @@ BuildRequires:  tex(latex)
 BuildRequires:  tex(ulem.sty)
 BuildRequires:  TOPCOM
 
+Requires:       libgfan%{_isa} = %{version}-%{release}
+
 Suggests:       TOPCOM
 
 %description
@@ -39,30 +43,45 @@ Requires:       %{name}%{?_isa} = %{version}-%{release}
 %description    doc
 Gfan examples and documentation files.
 
+%package        -n libgfan
+Summary:        Polyhedral computations related to polynomial rings
+
+# This can be removed once Fedora 28 has reached EOL
+Obsoletes:      gfanlib < 4.1.1
+Provides:       gfanlib = 4.1.1
+
+%description    -n libgfan
+Gfanlib has two major features:
+1) high-level exact polyhedral cone and polyhedral fan classes;
+2) fast exact mixed volume computation for lattice polytopes with overflow
+   checking.
+
+In particular, gfanlib is missing the Gröbner basis part of gfan.
+
+%package        -n libgfan-devel
+Summary:        Development files for libgfan
+Requires:       libgfan%{?_isa} = %{version}-%{release}
+Requires:       gmp-devel%{?_isa}
+
+# This can be removed once Fedora 28 has reached EOL
+Obsoletes:      gfanlib-devel < 4.1.1
+Provides:       gfanlib-devel = 4.1.1
+
+%description    -n libgfan-devel
+The libgfan-devel package contains libraries and header files for
+developing applications that use libgfan.
+
 %prep
 %setup -q -n %{name}%{version}
 %patch0
 %patch1
-
-fixtimestamp() {
-  touch -r $1.orig $1
-  rm -f $1.orig
-}
-
-# Fix the cddlib include paths
-sed -i.orig 's,cdd/,cddlib/,' src/{app_librarytest,lp_cdd,gfanlib_zcone}.cpp
-fixtimestamp src/app_librarytest.cpp
-fixtimestamp src/lp_cdd.cpp
-fixtimestamp src/gfanlib_zcone.cpp
+%patch2
 
 # Point to where the TOPCOM binaries will be installed
-sed -i.orig \
-  "s|^#define MINKOWSKIPROG.*|#define MINKOWSKIPROGRAM \"%{_bindir}/essai\"|" \
+sed -i.orig "s|^\(#define MINKOWSKIPROGRAM \).*|\1\"%{_bindir}/essai\"|" \
   src/minkowskisum.cpp
-fixtimestamp src/minkowskisum.cpp
-
-# Update the C++ standard slightly
-sed -i 's/-std=c++0x/-std=c++11/' Makefile gfanlib/Makefile.in
+touch -r src/minkowskisum.cpp.orig src/minkowskisum.cpp
+rm -f src/minkowskisum.cpp.orig
 
 # No need to install a simple upstream Makefile to rsync homepage
 # directory to upstream page.
@@ -72,7 +91,7 @@ rm -f homepage/Makefile
 make %{?_smp_mflags} CC=gcc CXX=g++ \
   OPTFLAGS="%{optflags} -DGMPRATIONAL -I%{_includedir}/cddlib" \
   PREFIX=%{_prefix} \
-  SOPLEX_LINKOPTIONS="$RPM_LD_FLAGS"
+  SOPLEX_LINKOPTIONS="-Wl,--as-needed $RPM_LD_FLAGS"
 
 # Build the manual
 pushd doc
@@ -84,18 +103,45 @@ dvipdf manual.dvi manual.pdf
 popd
 
 %install
+# Install the library
+mkdir -p %{buildroot}%{_libdir}
+cp -p src/libgfan.so.0.0.0 %{buildroot}%{_libdir}
+ln -s libgfan.so.0.0.0 %{buildroot}%{_libdir}/libgfan.so.0
+ln -s libgfan.so.0 %{buildroot}%{_libdir}/libgfan.so
+
+# Install the headers
+mkdir -p %{buildroot}%{_includedir}/gfanlib
+cp -p src/gfanlib*.h %{buildroot}%{_includedir}/gfanlib
+
+# Fix the headers
+for fil in %{buildroot}%{_includedir}/gfanlib/*.h; do
+  sed -i.orig 's,#include "\(.*\)",#include <\1>,' $fil
+  touch -r $fil.orig $fil
+  rm $fil.orig
+done
+
+# Install the binaries
+export LD_LIBRARY_PATH=%{buildroot}%{_libdir}
 make install PREFIX=%{buildroot}%{_prefix}
 pushd %{buildroot}%{_bindir}
     ./%{name} installlinks
 popd
 
+
 %check
+# Some tests depend on US English collation order
+export LC_ALL=en_US.UTF-8
+
 # The xfig test output varies slightly by architecture, and is non-critical,
 # so we skip that test.
 rm -fr testsuite/0009RenderStairCase
+export LD_LIBRARY_PATH=%{buildroot}%{_libdir}
 ./gfan _test
 
 
+%ldconfig_scriptlets -n libgfan
+
+
 %files
 %doc README doc/manual.pdf
 %license COPYING LICENSE
@@ -105,7 +151,19 @@ rm -fr testsuite/0009RenderStairCase
 %doc examples
 %doc homepage
 
+%files -n libgfan
+%doc gfanlib/README.txt
+%{_libdir}/*.so.*
+
+%files -n libgfan-devel
+%{_includedir}/gfanlib/
+%{_libdir}/*.so
+
+
 %changelog
+* Sat Jun  2 2018 Jerry James <loganjerry@gmail.com> - 0.6.2-3
+- Build and link with libgfan.so
+
 * Wed Feb 07 2018 Fedora Release Engineering <releng@fedoraproject.org> - 0.6.2-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild